*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Engine
There is a known issue with this vehicle and the fix by KIA is not safe nor fair to the consumer. Kia's knock sensor recall centers on the Knock Sensor Detection System (KSDS) software update for Theta II GDI engines. The update listens for rod bearing wear, triggers a check engine light and limp mode via Code P1326, and extends the engine warranty up to a lifetime or 15 years/150,000 miles. My problem is that we had to car in on May of 2026 after in went into limp mode. They updated the software. The car again went into limp mode on 10/21/2026, they updated the software again. My focus here is the fact that it is a known issue and they say it still does not meet the parameters for an…
Oct 21, 2026Service brakes, hydraulic
The contact owns a 2015 Kia Optima. The contact stated that while pulling into the driveway, the ABS warning light remained illuminated after the vehicle was powered off. The contact stated that the parking brake warning light unexpectedly illuminated while the vehicle was being operated. The contact stated that the brake lights illuminated while the vehicle was turned on or off. The contact's son inspected the vehicle and became aware that the rear of the vehicle near the brake pedal was extremely hot and that the area under the hood was extremely hot. The vehicle was taken to the dealer but was not diagnosed. The dealer informed the contact that the failure could be associated with a…
Sep 23, 2026 · 231,000 milesEngine
My energy in my car started messing up with only 150,000 miles it had a long knocking sound and it would not got over 20 miles while driving
Jun 10, 2026EngineFire
My 2015 KIA optima experienced a catastrophic engine fire while I was driving. There was no warning, I just heard a boom in the engine bay the breaks stopped working and all electrical cut out. As I'm coasting, because I'm unable to stop, flames started to come in through under the dash. I couldn't turn the car off, nor put it in park so the doors stayed locked. The driver window was opened just enough for me to grab the top and break it, allowing me to crawl out. The car coasted itself to the shoulder then blew up (I had a full tank of gas.). All this happened in the manner of 30 to 35 seconds. It's important to note that KIA just replaced the engine 2 months prior to this incident.
Aug 14, 2026Engine and engine cooling
The contact owns a 2015 Kia Optima. The contact stated that for over 8 years, the vehicle was experiencing excessive oil consumption. There was no warning light illuminated. The contact became aware that there was an oil leak on the ground underneath the vehicle. The vehicle was taken to the dealer on several occasions for the oil consumption failure; however, the dealer was unable to find a fault with the vehicle. The dealer had not yet provided a cause for the oil leak. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 123,000.
Aug 20, 2026 · 123,000 milesEngine
The engine in my vehicle failed while putting the car into reverse to back into my garage. I thank God I wasn't on the road when this happened. I took the car into a mechanic who confirmed that the engine was locked and that the car was very low on oil(even though I had my oil changed by him a few months prior). There was an undetected oil leak that led to the engine failure. The warning indicators didn't appear on my dash until after my engine failed.
Aug 14, 2026Engine
This is a formal vehicle safety complaint regarding a manufacturer's active refusal to remedy a known safety defect under an active recall campaign guidelines.My 2015 Kia Optima Turbo experienced an active internal mechanical engine knock, violent sputtering, and a complete engine seizure. The vehicle is currently sitting un-driveable at an authorized Kia dealership.The required Knock Sensor Detection System (KSDS) software update was successfully completed on this vehicle prior to the incident, legally qualifying it for a 100% free long-block engine replacement under the manufacturer's active Lifetime Warranty extension. However, the dealership service department is actively withholding…
Jul 27, 2026Electrical system
The contact owns a 2015 Kia Optima. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed; however, the rear taillight socket wiring harness failed to function as intended. The contact was informed that the brake lights were inoperable. The contact stated that the failure had occurred every 6â7 months. The contact stated that the repair was completed by the contact. The dealer was not made aware of the failure but provided no assistance. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 88,000.
Nov 10, 2025 · 88,000 miles
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.
